Potosí is the highest city of its size in the world (163,000 inhabitants at 3,977m altitude). It was founded by the Spaniards in 1545 after they discovered indigenous mine workers at Cerro Rico (described as the mouth of hell by one 16th century Spanish chronicler). Immense amounts of silver were once extracted and till today mining continues through small cooperatives extracting tin, zinc, lead and wolfram.

For many, the main reason for being in Potosí is to visit the mines and meeting and seeing the miners working in medieval conditions.

A mining tour starts with a visit to the miners market. This is where tourists buy gifts for the miners: a dynamite kit (3 USD), a bag of coca leafs (0.70 USD), a 96% alcoholic spirit (2 USD), ... Everything is available without any limits or restrictions

Then it's time for the hard part of the tour - going into the mines: entering the mines at +4,000m, crouching through narrow tunnels, temperature rising up to 40 ºC, breathing dusty air and noxious gases and seeing men - and even children - working in appalling conditions. A visit to the mines of Potosí is not for the faint-hearted.

Visitors to the mines must sign a paper accepting all risks of injury or death and waiving all responsibility. This is the third time while being in Bolivia that I need to sign such a waiver - anything is possible in crazy coca leaf country!